This project concerns the identification of cancer patterns within occupational groups that may reflect exposures in the work environment and investigation of methodological issues in occupational studies. Study groups are selected for a variety of reasons including 1) known or potential exposure to established or suspect carcinogenic substances, 2) prior case reports and studies suggesting an unusual cancer experience for the group, 3) requests by outside institutions and 4) availability of useful resources. Resources used include employment and death records maintained by companies; membership and death listings maintained by labor unions and professional organizations; and records from state or federal agencies. Studies during the past year include cohort mortality studies of persons employed in dry cleaning, non-agricultural pest control, chemical plants, non-ferrous smelters, taconite mines, and jewelry manufacturing. Proportionate mortality studies being conducted involve pharmaceutical workers, tobacco workers, petrochemical workers, pottery workers, chromate painters, fur dyers, veterinarians, metal platers, and embalmers. Death certificates are used to investigate occupational origins of leukemia and multiple myeloma, and cancers of the prostate and colon.